Answer: B) Informal.
Explanation: The style in writing can be defined as the way a writer writes. It is the technique that an individual author uses in his writing. It varies from author to author, and depends upon one's syntax, word choice, and tone. In the given excerpt from a student's analytical essay, we can see an example of an informal style of writing, we can see that in the use of informal language like "cool," "Alice does not really get it," etc.